Saturday, January 29, 2005

Stray voltage -- or dumped electricity?

The dramatic effects of "stray voltage" from the wind facility in Kewaunee County, Wisconsin, seem to be awfully extensive for simple leakage from the buried transmission lines, particularly as those lines were brand new.

The electrician who helped the affected farmers noted that except in California there is no limit in the U.S. of how much electricity can be dumped into the ground. Consider, then, the fundamental problem of aerogenerators on the grid: Their production depends on the wind and cannot be adjusted according to actual demand (the grid must keep production and consumption in constant balance). What, then, is done when the grid is meeting demand and the wind rises unnecessarily? The electricity from the aerogenerators is an excess and must be dumped. In western Denmark, the grid operator calculates that 84% of the wind-generated power must be exported, because it is not needed when it is produced.

Wind facilities complicate the balancing act of the grid. In Ireland, connections were halted last year because of the instability they cause. The German grid operator Eon Netz describes the problem of wind-generated power suddenly dropping off and the unpredictability of production levels, requiring substantial backup facilities that would seem to negate any benefit claimed for the aerogenerators.

Yet they are highly profitable because of tax breaks, mandated sales, and, most significantly, the market for "renewable energy credits" (or "renewables obligation certificates"). Logically, the best situation for a utility involved in a wind facility would be to not have to deal with its erratic supply yet still be able to enjoy the sale not only of the power produced but the "green credits" as well. They need only record the power that arrives at a substation from all of the turbines and then "ground" it whenever it's not actually needed, which is most of the time. The utility sells what is produced whether or not it is actually used.

Other production plants can adjust their output, but aerogenerators can't. Theirs is subject only to the wind. The only way to control it is to direct it into the ground instead of the grid. Is this what is happening in Kewaunee County? Is this the normal design of wind "farms"?